The present disclosure relates to a video signal processing apparatus and a video signal processing method which process video signals and supply the same to a liquid crystal display device to cause the liquid crystal display device to perform overdrive which reduces motion image blur by compensating the response speed of the liquid crystals.
As described in Japanese Patent Laid-open Publication No. 2005-148521 (PTL 1) and No. 2010-197548 (PTL 2), in order to improve the display characteristics of motion images, the liquid crystal display apparatus generally includes a frame rate converter which converts the frame frequency of video signals by a severalfold factor, such as a doubled or quadrupled frequency. The liquid crystal display device receives the video signals with the frame rate increased by the frame rate converter for displaying video.
Moreover, as described in PTLs 1 and 2, the liquid crystal display device includes an overdrive processing unit which reduces motion image blur by compensating the response speed of the liquid crystals. The overdrive is also referred to as “temporal emphasis” that emphasizes high-frequency components along the time-axis.
In order to overdrive the liquid crystal display device by using the overdrive processing unit, video signals of a current frame and video signals of the previous frame are necessary. The previous frame is obtained by using a frame memory to delay the video signal of the current frame by one frame.